Hopes for cancer treatment 'unearthed'

Low levels of a chemical found in the soil could be contributing to Britain's poor record on cancer, scientists say.

Researchers at Edinburgh University said falling levels of selenium in UK diets could be increasing people's risk of developing lung, colon and corectal cancers as well as skin cancer.

Experiments found that skin cells became more resistant to ultraviolet rays when they were treated with selenium compounds.

Researchers say selenium could also be used to slow down the skin's ageing process, which is largely the result of exposure to sunlight.

Roddie McKenzie, of the university's department of dermatology, said the discovery could pave the way for selenium-based treatments for cancer.

He said levels of the chemical - which occurs naturally in the soil - had fallen to the point where people in Britain were receiving as little as 40 per cent of the recommended daily intake in their diets.

Selenium levels are lower in northern European countries such as Britain than in the Mediterranean or North America.

In parts of China - where selenium levels in the soil are at their lowest - selenium deficiency is linked to Keshan Disease, which causes poor heart function.

Some studies in the United States found that selenium supplements given to test groups appeared to reduce their chance of contracting cancer by as much as 50 per cent.

Mr McKenzie said: "There has been concern over the last five years or so that levels of selenium in people's blood have been falling.

"This is a concern because selenium is necessary for the optimal functioning of the immune system."

Mr McKenzie said research suggested that selenium had a dual function of protecting skin cells against ultraviolet (UV) radiation and stimulating the enzymes to repair the damage which it causes.

He added that selenium compounds could be given as a dietary supplement or in the form of a skin cream to protect against the harmful effects of sunlight.